Junction box



June 16, 1936. H. R. THOMPSON 2,044,650

' JUNCTION BOXH Filed July 20, 1955 flan/r7 E. Them 5017 Patented June 16, 1936 ITED STATES PATENT OFFICET HenryRedfield Thompson, East Falls Church,

-Va., assignor oi. one-half to Edward T. Fenwick, East Falls Church, Va.

Application July 20, 1935, Serial No. 32,457

6 Claims. (01. 247-21) This invention relates generally to junction boxes such as are in common use for receiving the endsof wiring in electric systems, adapted to be connected to each other, or to the terminals of a switch mounted therein.

When boxes of this type'are used in lath and plaster'walls, or in walls formed of fibrous ma- .terial, it is usually very difiicult to secure the junction or switch boxes firmly in position. The main object of the present invention is to eliminate this defect in such junction boxes, and to provide aflmeans by which these boxes may be firmly secured on lath and plaster or fiber board walls Other objects of the invention will become apparent as the detailed description thereof proceeds; Injthe drawing:

Figure 1 is an elevation 01! a switch box embodying the present invention, the cover plate being broken away to show details or construction; h

Figure 2 is an elevation to an-enlarged scale removed therefrom;

3-3 of Figure 2;

Figure 4 is a horizontal section taken on the line H of Figure 3; and Figure 5 is a perspective viewoi an angle plate forming one o! the essential elements of this invention.

- As shown in the drawing. the invention com- "prises a switch box I of standard construction, and having its sides and rear wall provided with the usual circular weakened portions 2, adapted to be knocked out to receive the ends of wiring intended to be spliced to each other, either directly, or through the medium of a switch. Boxes 4 -01 this type have their upper and lower end walls provided with laterally deflected lugs 3' and ,4,

having screwthreaded apertures 5 and 8, to receive machine screws I for the purpose of secur ing a cover 8, in position.

The upper and lower walls a and III are pro vided with the usual securing plates II and I2,

respectively, each of which is provided at its 'op posite ends with inwardly directed bifurcated arms I3 and I4, (see Figure 4) adjustably mounted on said walls and adapted to be secured in adjusted position with respect to the trout edge of the box by means of the set screws I8 tapped into screwthreaded apertures in said upper and lower end wallsof the box-shown in Figure 1, with the cover plate As so far described, the, junction "at is stand-i ard and in common use. The adjustment or the securing plates I I and I 2 with respect to the front edge of the box I depends upon the thickness or plaster or other finish on the wall where thebox is designed for use. In this old form, it is com 5 mon to use ordinary wood screws for fastening the securing plates II and." to lath and plaster, or to plugs driven in brick walls. 'It is not always possible to have the screws encounter wood laths in the common lath and plaster walls, and it 10 is difficult to drive plugs into brick or tile walls where it is necessary "to have the screws very close to the edges of the opening intended to receive the junction box. It is practically impossible tosecure devices of this type firmly to 15 wallboard which is commonly made of compressed paper or compressed'flber and therefore very have provided the upper and lower end walls with slots I6 and I1 adapted to receive slidably'the narrow neck I8 of an angle plate designated generally by the reference numeral Is. This plate I9, on one end of the neck I8, is shaped to form a T-head 20, while the other end of the .neck I8 is shaped to provide a comparatively broad plate 2t, having screwthreaded-apertures 22 and 23 therethrough to receive the screwthreadecl shanks of, the headed machine screws;

It can be readily seen from Figure -3 0! the drawing, that in practicing this'invention the only change involved in the standard box is that required by the iormation oi the slots I6 and II.

This change, of course, can be eflected with practically no additional best, since it requires nothing more than a slight addition to the die commonly used for stamping the rear and opposite end walls from sheet metal.

Obviously, the plates I9 can also be stamped 40 very readily from sheet metal; and can be veryreadily assembled by passing the T-head 20 and neck I8 through the slots I6 and I1 as a preliminary to using the box in connection with a lath and plaster. or fiber board wall. In setting 4 the box into the opening, the upper plate I9 will lie fiat of its own weight against the upper wall 9. The lower plate can be held fiat by the operator engaging the head 20 and holding it in such posi-. tion until it shall have passed beyond the inner face of the wall W. Withthe securing plates properly adjusted for the depth of plaster or other finish, it will be evident that the mechanic canreadily manipulate the plates I9 toward the receive the machine screws 24. When this is done, it is evident that it would be practically impossible to jar the box loose from the wall, or even to pull it apart from the wall without practically destroying the wall.

What I claim is:

1. A junction box having securing plates adjustable toward and from the front edge of said box on opposite end walls thereof, said walls,

being provided with slots extending substantially at right angles to said edge, clamping plates slidable on said walls along said slots toward and from said securing plates, and means extending through said securing plates for adjusting said clamping plates toward said securing plates.

2. A junction box having securing plates adjustable toward and from the front edge of said box on opposite end walls thereof, said walls being provided with slots extending substantially at right angles to said edge, clamping plates slidable on said walls along said slots toward and from said securing plates, and means extending through said securing plates for adjusting said clamping plates toward said securing plates, said clamping plates being rotatable from folded positions against said walls into positions at right angles thereto.

3. A junction box having securing plates adjustable toward and from the front edge of said box on opposite end walls thereof, said walls being provided with slots extending substantially at right angles to said edge, clamping plates slidable on said wallsalong said slots toward and from said securingv plates, means extending through said securing plates for adjusting said clamping plates toward said securing plates, said clamping plates being rotatable from folded positions against said walls into positions at right box on one wallthereof, said wall being provided with a slot extending substantially at right angles to said edge, a clamping plate slidable on said wall along said slot toward and from said securing plate, and means extending through said 10 securing plate for adjusting said clamping plate toward said securing plate. V

5. A junction box having a securing plate adjustable toward and from the front edge of said box on one wall thereof, said wall being provided 15 with a slot extending substantially at right angles to said edge, a-clamping plate slidable on said wall along said slot toward and from said securing plate, and means extending through said securing plate for adjusting said clamping plate 20 toward said securing plate, said clamping plate being rotatable from folded position against said wall into a position at right angles thereto.

6. A junction box having a securing plate adjustable toward and from the front edge of said 25 box on one wall thereof, said wall being provided with a slot extending substantially at right angles to said edge, a clamping plate slidable on said wall along said slot toward and from said securing plate, means extending through said securing 30 plate for adjusting said clamping plate toward said securing plate, said clamping plate being rotatable from folded p'osition'against said wall into a' position at right angles thereto and having a part extending through said slot to the interior 35 of the box to eiTect said rotation.

HENRY REDFIELD THOMPSON. 

